摘要
采用选晶法在改进型Bridgman定向凝固炉中制备镍基单晶高温合金DD403,利用电子探针(EPMA)技术研究了DD403合金在枝晶生长条件下的显微偏析。结果表明,随着抽拉速率增加DD403的偏析程度逐渐加剧。偏析于枝晶间元素Al、Ti和枝晶干元素Co、W的偏析程度随着抽拉速率的增加而增大,而合金元素Mo和Cr的偏析比接近于1,基本不存在偏析,且偏析比随抽拉速率增加没有明显变化。研究结果同时表明,随着抽拉速率增加DD403的共晶含量逐渐增加。
Ni-based single crystal superalloy DD403 was processed with withdrawal rates between 30and150μm/s.Electron probe micro-analyzer(EPMA)technique was used to investigate the microsegregation of DD403.The as-cast microstructures and microsegregation were characterized as a function of the withdrawal rate.The results indicate that elements Al and Ti segregate to the interdendritic region,Co and W segregate to the dendrite core.The segregation degree of elements Al,Ti,Co and W increase with increasing withdrawal rate at the range of 30~150μm/s.Elements Mo and Cr do not exhibit any significant tendency to segregate to either the dendrite core or the interdendritic regions during solidification.The results also show that the volume fraction ofγ-γ′eutectic increase with increasing withdrawal rate at the range of 30~150μm/s.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2015年第6期800-803 799,799,共5页
Journal of Materials Science and Engineering
基金
西北工业大学凝固技术国家重点实验室开放课题资助项目(SKLSP201407)
华能集团科技资助项目(HNKJ12-H22)
关键词
镍基单晶高温合金
定向凝固
显微偏析
共晶
Ni-based single crystal superalloy
directional solidification
microsegregation
eutectic
